TY - JOUR
TI - Water vapour retrieval using the Precision Solar Spectroradiometer
AU - Raptis, P.I.
AU - Kazadzis, S.
AU - Gröbner, J.
AU - Kouremeti, N.
AU - Doppler, L.
AU - Becker, R.
AU - Helmis, C.
JO - Atmospheric Measurement Techniques
PY - 2018
VL - 11
TODO - 2
SP - 1143-1157
PB - Copernicus GmbH
SN - null
TODO - 10.5194/amt-11-1143-2018
TODO - AERONET;  GPS;  instrumentation;  irradiance;  measurement method;  microwave radiometer;  precision;  radiosonde;  solar radiation;  spatial resolution;  uncertainty analysis;  water vapor, Brandenburg [Germany];  Germany;  Lindenberg
TODO - The Precision Solar Spectroradiometer (PSR) is a new spectroradiometer developed at Physikalisch-Meteorologisches Observatorium Davos - World Radiation Center (PMOD-WRC), Davos, measuring direct solar irradiance at the surface, in the 300-1020nm spectral range and at high temporal resolution. The purpose of this work is to investigate the instrument's potential to retrieve integrated water vapour (IWV) using its spectral measurements. Two different approaches were developed in order to retrieve IWV: the first one uses single-channel and wavelength measurements, following a theoretical water vapour high absorption wavelength, and the second one uses direct sun irradiance integrated at a certain spectral region. IWV results have been validated using a 2-year data set, consisting of an AERONET sun-photometer Cimel CE318, a Global Positioning System (GPS), a microwave radiometer profiler (MWP) and radiosonde retrievals recorded at Meteorological Observatorium Lindenberg, Germany. For the monochromatic approach, better agreement with retrievals from other methods and instruments was achieved using the 946nm channel, while for the spectral approach the 934-948nm window was used. Compared to other instruments' retrievals, the monochromatic approach leads to mean relative differences up to 3.3% with the coefficient of determination (R2) being in the region of 0.87-0.95, while for the spectral approach mean relative differences up to 0.7% were recorded with R2 in the region of 0.96-0.98. Uncertainties related to IWV retrieval methods were investigated and found to be less than 0.28cm for both methods. Absolute IWV deviations of differences between PSR and other instruments were determined the range of 0.08-0.30cm and only in extreme cases would reach up to 15%. © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License.
ER -